Venous HbA1c Research Articles

Analysis of HbA1c using microfluidic card (Capitainer qDBS card) as a pre-step before determination of the HbA1c value with an immunological method

The objective of the study was to evaluate Capitainer’s quantitative dried blood spots (qDBS) card for Hemoglobin A1c (HbA1c) testing. qDBS cards can be used for at-home sampling for HbA1c determination in a Swedish laboratory setting. A total of 153 routine requested HbA1c samples were used in this evaluation of microfluidic cards (qDBS). The HbA1c was extracted from the disc and HbA1c was determined at cobas 6000 instruments with immunological technology. The results were compared with results from traditional venous HbA1c testing. The reproducibility of using this elution procedure was 4.0% measured as coefficient of variation at a HbA1c concentration of 51 mmol/mol. Analytical performance specifications for HbA1c < 52 mmol/mol using DBS card (c501) compared with assigned values from Capillarys 3 was (y) = 1.03 x Capillarys 3(x) − 0.87; R2 = 0.97. There is a good agreement between HbA1c determined by traditional HbA1c testing and determination from Capitainer’s qDBS cards. This shows that the technology could be used for out-of doctor’s office testing.

Using point-of-care HbA1c to facilitate the identification of diabetes and abnormal glucose regulation in primary healthcare settings.

Glycated hemoglobin A1c (HbA1c) is a critical index for the diagnosis and glycemic control evaluation of diabetes. However, a standardized method for HbA1c measurement is unaffordable and unavailable among the Chinese population in low-resource rural settings. Point-of-care (POC) HbA1c testing is convenient and inexpensive, but its performance remains to be elucidated. To investigate the value of POC HbA1c for identifying diabetes and abnormal glucose regulation (AGR) in the resource-limited Chinese population. Participants were recruited from 6 Township Health Centers in Hunan Province. Samples for POC HbA1c, venous HbA1c, fasting plasma glucose, and 2 h-plasma glucose were obtained after physical examination. The oral glucose tolerance test was performed as the gold standard for diagnosis. The diagnostic capacities of the POC HbA1c measurement in predicting undiagnosed diabetes and AGR were evaluated. Among 388 participants, 274 (70.6%) normoglycemic controls, 63 (16.2%) prediabetes patients, and 51 (13.1%) diabetes patients were identified with oral glucose tolerance test (OGTT). Meanwhile, among 97 participants who underwent two HbA1c detection methods simultaneously, a positive correlation was found between POC HbA1c and standardized HbA1c (r = 0.75, P < 0.001). No notable systematic difference was observed from the Bland-Altman Plots. The POC HbA1c cutoff values were 5.95 and 5.25%, which efficiently identified diabetes (AUC 0.92) and AGR (AUC 0.89), respectively. The alternative POC HbA1c test efficiently discriminated AGR and diabetes from normoglycemia, especially among the Chinese population in primary healthcare settings.

Comparison of central laboratory HbA1c measurements obtained from a capillary collection versus a standard venous whole blood collection in the GRADE and EDIC studies.

BackgroundWe compared HbA1c values obtained from capillary blood collection kits versus venous whole blood collections in study participants with type 1 or type 2 diabetes.MethodsA total of 122 subjects, 64 with type 2 diabetes participating in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness (GRADE) Study and 58 with type 1 diabetes from the Epidemiology of Diabetes Interventions and Complications (EDIC) Study, participated in the validation study. Capillary tubes were filled by fingerstick by the participants on the same day as the collection of venous whole blood samples in EDTA-containing test tubes and were mailed to the central laboratory. HbA1c in all samples was measured with the same high-performance liquid chromatography. GRADE participants also completed a questionnaire on the ease of performing capillary collections.ResultsParticipants from 22 clinical centers (GRADE n = 5, EDIC n = 17) were between 35 and 86 years of age, with 52% male and diverse race/ethnicities. Venous HbA1c results ranged between 5.4–11.9% (35.5–106.6 mmol/mol) with corresponding capillary results ranging between 4.2–11.9% (22.4–106.6 mmol/mol). The venous and capillary results were highly correlated (R2 = 0.993) and 96.7% differed by ≤0.2% (2.2 mmol/mol). Of participants surveyed, 69% indicated that the instructions and collection were easy to follow and 97% felt the collection method would be easy to do at home.ConclusionsThe capillary blood HbA1c results compared well with the conventional venous whole blood results. The capillary kits can be employed in other studies to reduce interruption of critical data collection and potentially to augment clinical care when in-person visits are not possible.

Accuracy of a Point-of Care Hemoglobin A1c Assay - A Community Outreach Project

Glycated hemoglobin (HbA1c) is an invaluable tool in diabetes mellitus (DM) management. Conventionally obtained via venous blood sampling, point-of-care (POCT) capillary HbA1c measurement offers an opportunity for immediate treatment modification, reduced cost & increased patient satisfaction. While previous studies using the POCT HbA1c test A1cNow+ have shown accuracy within a 0.5% range from the gold standard venous HbA1c, we noted discrepancy in our community health clinic & sought to evaluate the accuracy of POCT HbA1c levels compared to venous HbA1c levels to guide our clinical decision-making.In this 2-part study, we compared POCT HbA1c levels measured via a single use A1CNow+ HbA1c monitoring device & venous HbA1c samples measured by a standardized lab. Part1: after retrospective chart review, we identified 262 patients with prediabetes, Type1 or Type2 DM based on ADA guidelines who attended our clinic from January 2019-June 2019 & received POCT HbA1c with A1cNow+ testing during their visit. Of those cases, 47 patients also had a venous HbA1c at a standardized laboratory within 1 month of having their POCT HbA1c performed in our clinic. Part2: We noted variability in the temperature storage of A1CNow+ test strips. Storage was standardized to room temperature as per device instructions in June 2019. We subsequently reviewed charts from June 2019-December 2019 & identified 118 patients who had both POCT HbA1c & venous HbA1c measurement within a 1 month period.Patients was categorized into subgroups per ACP guidelines for DM control: prediabetic (HbA1c 5.7–6.4%), controlled DM (HbA1c 6.5 to 8.0%) & uncontrolled DM (HbA1c >8.0%). The average difference between POCT & venous HbA1c tests was calculated & analyzed for statistical significance using paired t test analysis. Part1: For patients in prediabetic, controlled & uncontrolled DM subgroups, the mean difference between A1cNow+ & standardized venous HbA1c testing was 0.68% (p= 0.004), 1.15% (p= <0.0001) and 1.36% (p= 0.0003) respectively. Part2: After standardization of test strip storage, the mean difference between A1cNow+ & venous HbA1c testing for prediabetic, controlled & uncontrolled DM patients was 0.33% (p= 0.002), 0.41% (p= 0.011) and 1.26% (p= <0.0001) respectively.POCT HbA1c provides a unique opportunity to immediately address glycemic control. Its advantages are especially apparent in a patient population with limited resources & poor follow up, as in our clinic. Although standardizing test storage improved overall concordance between A1cNow+ HbA1c testing & venous HbA1c, there was still a statistically significant larger mean difference in uncontrolled DM patients. In prediabetic & controlled DM patients, however, POCT HbA1c was accurate within previously published reports of a 0.5% range when compared to venous HbA1c. An algorithm has since been developed to guide our clinical decision making with these findings.

Prevalence of gestational diabetes mellitus based on various screening strategies in western Kenya: a prospective comparison of point of care diagnostic methods

BackgroundEarly diagnosis of gestational diabetes mellitus (GDM) is crucial to prevent short term delivery risks and long term effects such as cardiovascular and metabolic diseases in the mother and infant. Diagnosing GDM in Sub-Saharan Africa (SSA) however, remains sub-optimal due to associated logistical and cost barriers for resource-constrained populations. A cost-effective strategy to screen for GDM in such settings are therefore urgently required. We conducted this study to determine the prevalence of gestational diabetes mellitus (GDM) and assess utility of various GDM point of care (POC) screening strategies in a resource-constrained setting.MethodsEligible women aged ≥18 years, and between 24 and 32 weeks of a singleton pregnancy, prospectively underwent testing over two days. On day 1, a POC 1-h 50 g glucose challenge test (GCT) and a POC glycated hemoglobin (HbA1c) was assessed. On day 2, fasting blood glucose, 1-h and 2-h 75 g oral glucose tolerance test (OGTT) were determined using both venous and POC tests, along with a venous HbA1c. The International Association of Diabetes in Pregnancy Study Group (IADPSG) criteria was used to diagnose GDM. GDM prevalence was reported with 95% confidence interval (CI). Specificity, sensitivity, positive predictive value, and negative predictive value of the various POC testing strategies were determined using IADPSG testing as the standard reference.ResultsSix hundred-sixteen eligible women completed testing procedures. GDM was diagnosed in 18 women, a prevalence of 2.9% (95% CI, 1.57% - 4.23%). Compared to IADPSG testing, POC IADPSG had a sensitivity and specificity of 55.6% and 90.6% respectively while that of POC 1-h 50 g GCT (using a diagnostic cut-off of ≥7.2 mmol/L [129.6 mg/dL]) was 55.6% and 63.9%. All other POC tests assessed showed poor sensitivity.ConclusionsPOC screening strategies though feasible, showed poor sensitivity for GDM detection in our resource-constrained population of low GDM prevalence. Studies to identify sensitive and specific POC GDM screening strategies using adverse pregnancy outcomes as end points are required.Trials registrationClinical trials.gov: NCT02978807, Registered 29 November 2016.

The prevalence, risk factors, and screening measure for prediabetes and diabetes among Emirati overweight/obese children and adolescents.

BackgroundThe aim of the study was to estimate the prevalence of prediabetes and type 2 diabetes (T2D) among overweight/obese children and adolescents using different diagnostic/screening methods in comparison.MethodsWe recruited overweight/obese Emirati students; grade 6–12 (age 11–17 years) from 16 government schools in Sharjah (UAE). Anthropometric, demographic, and clinical history data was measured by standard methods. Body mass index (BMI) was categorized according to BMI percentile charts for age and sex – CDC. Capillary fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) were measured by finger prick test, followed by confirmatory oral glucose tolerance tests (OGTT) and venous HbA1c for students with abnormal capillary FBG and/or HbA1c.ResultsOf a total of 1034 participants (45 % females) median age 14.7 years, 443 (43 %) students had abnormal screening results. The prevalence of prediabetes and T2D was 5.4 % and 0.87 %, respectively, based on OGTT (gold standard). HbA1c showed a considerable discrepancy regarding the prevalence of prediabetes (21.9 %), but not diabetes. There was a statistically significant difference in the BMI Z-scores between the three different groups of students showing normal glycemic testing, prediabetes and T2D (p = 0.041). Univariate logistic regression analysis showed that glycemic status was significantly associated with family history of T2D first-degree relatives [OR 1.87: 95 % CI: 1.04–3.36; P = 0.036], parents employment [OR 1.79: 95 % CI: 1.06–3.02; P = 0.029] and levels of triglycerides [OR 2.28: 95 % CI: 1.11–4.68; P = 0.024].ConclusionsThe prevalence of prediabetes and diabetes was high among overweight/obese Emirati children and adolescents. The numbers for prediabetes were considerably higher when using HbA1c as compared to OGTT. Overall adiposity, family history of T2D, employment and high levels of triglycerides were risk factors associated with abnormal glycemic testing.

Collection and laboratory methods for dried blood spots for hemoglobin A1c and total and high-density lipoprotein cholesterol in population-based surveys

BackgroundThe Health Measures at Home Study was a study designed to evaluate the feasibility of incorporating dried blood spots (DBS) collection into the National Health Interview Survey and to compare the proficiencies between field interviewers and health technicians in obtaining DBS. MethodsDBS collection and venipuncture were attempted on 125 participants. The DBS were collected in the participant's home and venous blood was collected in the National Health and Nutrition Examination Survey (NHANES) mobile examination center. The DBS results were compared to venous results in the NHANES for the measurements of hemoglobin A1c (HbA1c) and total and high-density lipoprotein (HDL) cholesterol. ResultsField interviewers and health technicians were able to collect the DBS for greater than 95% of participants. For DBS, health technicians and field interviewers were highly correlated for HbA1c (r=0.92) and total cholesterol (r=0.89), but not for HDL cholesterol (r=0.72). The DBS results of interviewers and health technicians compared to the venous method for HbA1c (r=0.90), but did not compare well for HDL cholesterol (r=0.64–0.66) and total cholesterol (r=0.65–0.67). ConclusionDBS was comparable to venous HbA1c, but not for total and HDL cholesterol. Health technicians and field interviewers had similar performance for DBS methods, except HDL cholesterol.

Cross-sectional comparison of point-of-care with laboratory HbA1c in detecting diabetes in real-world remote Aboriginal settings

ObjectivesTo determine if point-of-care (POC) glycated haemoglobin (HbA1c) is sufficiently accurate in real-world remote settings to predict or exclude the diagnosis of diabetes based on laboratory HbA1c measurements.DesignCross-sectional study comparing...

Structured, intensive education maximising engagement, motivation and long-term change for children and young people with diabetes: a cluster randomised controlled trial with integral process and economic evaluation – the CASCADE study

Structured, intensive education maximising engagement, motivation and long-term change for children and young people with diabetes: a cluster randomised controlled trial with integral process and economic evaluation – the CASCADE study

Validation of Finger-Prick Testing of Fasting Blood Glucose, Total Cholesterol, and HbA1c in Adolescents

This study compared finger-prick testing of fasting blood glucose, total cholesterol, and glycated hemoglobin (HbA1c) with venous blood method in the screening of Jamaican adolescents in a school setting. Subjects, aged 14 to 18 years, were selected from grades 9 to 12, in 10 randomly selected high schools on the island. Capillary whole blood was tested for fasting blood glucose using the Accu-Chek Advantage Blood Glucose Monitor (Roche Diagnostics, Auckland, New Zealand). The Accutrend GCT Cholesterol Monitor (Roche Diagnostics, Mannheim, Germany) was used for measuring total cholesterol. HbA1c was tested using the NycoCard (Axis-Shield, Oslo, Norway). Finger-prick testing was compared to venous blood using standard laboratory procedures for all 3 tests. A total of 59 students participated, whose mean age was 15.6 (1.2) years. Mean fasting blood glucose finger-prick values (92.88 ± 11.97 mg/dL) was not significantly different (P > 0.05) from venous values (95.24 [10.27] mg/dL). Mean venous value of total cholesterol (157.9 [30.0] mg/dL) was significantly higher (P < 0.01) than finger-prick (145.8 [21.6] mg/dL). Mean venous HbA1c (5.40% [0.81%]) was significantly lower (P < 0.01) than finger-prick (6.08% [1.5%]). Percentage bias between the 2 methods met the reference standards for fasting blood glucose and total cholesterol but not for HbA1c. Bland-Altman tests of agreement between the 2 methods indicated good agreement for all 3 tests. Finger-prick testing of fasting blood glucose compared favorably with venous testing and may be used for screening this population. The Bland Altman tests indicated that finger-prick testing of fasting blood glucose, total cholesterol, and HbA1c may be used for the screening of adolescents in a high school setting.

Prevalence of type 2 diabetes and other cardiovascular risk factors in Mayotte in 2008: The MAYDIA study

Aim Mayotte, a French overseas territory located in the Indian Ocean, has never had a previous estimate of diabetes prevalence, but has recently undergone socioeconomic changes leading to lifestyle modifications. For this reason, a survey was carried out in 2008 to estimate the prevalence of diabetes and cardiovascular risk factors in the island's population. Methods A three-step, randomized sample of 1268 individuals, aged 30–69 years, was home-screened, using capillary blood glucose and capillary HbA 1c, weight, height, waist circumference and two blood-pressure measurements. Those with a history of diabetes, glucose ≥1 g/L (fasting) or ≥1.40 g/L (non-fasting), or HbA 1c ≥ 6%, and a subgroup of those with normal results were examined at a healthcare centre to measure venous HbA 1c and glucose, and to diagnose diabetes, using an oral glucose tolerance test. Results The weighted prevalence of diabetes (venous plasma glucose ≥1.26 g/L at fasting and/or ≥2 g/L at 2 h, or treatment with oral hypoglycaemic agents or insulin) was 10.5% (95% CI: 8.2–13.4%). This increased with age from 3% at age 30–39 years to 26% at age 60–69 years, with no gender differences. Also, more than 50% of those with diabetes were unaware of it, while half of those treated for diabetes still had HbA 1c levels >7%. The prevalence of overweight (BMI: 25–29 kg/m 2) was estimated to be 35% in men and 32% in women, while obesity (≥ 30 kg/m 2) was estimated to be 17% in men and 47% in women. Conclusion The high prevalence of obesity combined with a high prevalence of diabetes indicates a potential for further increases in the prevalence of diabetes and cardiovascular disease in Mayotte. Preventative action against obesity, diabetes and hypertension is required now, as well as plans for appropriate healthcare delivery in the island.

Validation of Finger‐Prick Testing of FBG, TC, and HbA1c in Adolescents

The study compared finger‐prick testing of FBG, TC and HbA1c with venous blood method in Jamaican adolescents in a school setting. Adolescents ages 14–18 years were studied. Subjects were randomly selected from grades 9–12, in ten high schools on the island. Capillary whole blood was tested for fasting blood glucose, total cholesterol, and HbA1c. Finger‐prick testing was compared tovenous blood using standard laboratory procedures for all three tests. A total of 59 adolescents participated, mean age was 15.6±1.2 years. Mean FBG values were 92.97±11.98 for finger‐prick and 95.24±10.27 for venous sample. No significant difference was found for methods of testing for FBG (p &gt;.05). Mean venous value of TC(157.9±30.0) was significantly higher (p &lt;.01) than finger‐prick (145.8±21.6). Mean venous HbA1c (5.40±0.81) was significantly lower (p&lt;.01) than finger‐prick (6.08±1.5). Percentage bias between the two methods met the reference standards for FBG, and TC but not for HbA1c. Bland Altman tests of agreement between the two methods indicated good agreement for all three tests. Finger‐prick testing of FBG compared favorably with venous testing and may be used for screening this population. The Bland Altman tests for agreement indicated that finger‐prick testing of FBG, TC, and HbA1c may be used for the screening of adolescents. Supported by a grant from FIU Foundation.